The term "phospholipid," also known as lecithin, as used herein does not refer only to a single phospholipid, such as phosphatidylcholine, but rather may comprise de-oiled granules or powder having approximately the following typical composition (Orthoefer, F., Lecithin and Health, Vital Health Pub, Bloomingdale, IL, p. 21.):
Phosphatidylcholine 23% Phosphatidylethanolamine 21% Phosphatidylinositol 19% Phosphatidic Acid 6% Glycolipids 14% Other phospholipids 15%
In addition, the term "phospholipid" or lecithin also comprises any enriched phospholipid compound in which the phosphatidylcholine content exceeds 23%, the phosphatidylinositol content exceeds 19%, or the phosphatidylethanolamine exceeds 21%.
It has been known to use lecithin as an ingredient or a constituent in formulations for soaps, creams, and lotions, as well as other emulsions applied to the skin. These various emulsions containing lecithin have been used to moisturize skin and as medicated ointments for general applications, with the various emulsions and ointments rubbed onto the user's skin. In these formulations, lecithin serves the following purposes: 1) it is an emulsifier to promote solubilization of non-aqueous soluble components or medications into the aqueous phase, 2) it contributes to the stability of the emulsion, 3) it is an excellent moisturizer, 4) it delivers highly beneficial phospholipids to the skin, and 5) it contains vitamin E and polyunsaturated fats, both of which impart health benefits to the user's skin. While such emulsions and creams are useful in reducing dry skin, they are difficult to apply and leave a greasy or sticky feeling on the user's skin. The non-aqueous portions of the known emulsions are often simply oils which do not replenish moisture or oils lost from the skin. Thus, it would be desirable to have an ointment, treatment, or emulsion, which is easy to apply and does not leave a sticky or greasy feeling on a user's skin, but which is useful in moisturizing the skin, maintaining softness, and preventing loss of water and natural oils.
Lecithin is derived from soybeans and can be produced in liquid, powdered or granular form. While lecithin has been used in emulsions, products based only on phospholipids are few. U.S. Pat. No. 5,498,607 to Hsia et al. describes use of a topically applied phosphatidylcholine fraction of lecithin to reduce cholesterol. U.S. Pat. No. 4,221,784 to Grower et al. describes the oral administration of lecithin alone to restore memory loss. Administered in conjunction with the American Heart Association Step I diet, lecithin enhances the reduction of plasma cholesterol and LDL. In addition, lecithin is effective in reducing total cholesterol and triglycerides in hypercholesterolemic hamsters (Wilson, T., et al., "Soy Lecithin Reduces Plasma Lipoprotein Cholesterol and Early Atherogenisis in Hypercholesterolemic Monkeys and Hamsters: Beyond Linoleate", Atherosclerosis (1998) 140:147-153).
The positive effects of lecithin in reducing arterial plaque, besides decreasing LDL cholesterol, and increasing HDL cholesterol, are well known (Wojcicki, J. et al., "Clinical Evaluation of Lecithin as a Lipid-lowering Agent"; Hunt, C. et al., "Hyperlipoproteinaemia and Atherosclerosis in Rabbits Fed Low-level Cholesterol and Lecithin", British J. of Experimental Pathology (1985) 66: 35-46; FASEB, "Effects of Consumption of Choline and Lecithin on Neurological and Cardiovascular Systems" (1981, August).
U.S. Pat. No. 4,783,450 to Fawzi et al. describes the use of lecithin as a skin penetration enhancer designed for transdermal applications, in which the described skin is mucosal and bronchial. Kato ("Effect of Egg Yolk Lecithin on Transdermal Delivery of Bunazosin Hydrochloride", J. of Pharmacy and Pharmacology" (1987 May) 39(5): 399-400) and Willimann ("Lecithin Organogel as Matrix for Transdermal Transport of Drugs", J. of Pharmaceutical Sciences (1992 September) 81(9): 871-874) report on the effectiveness of egg lecithin and lecithin gels as efficient carriers of drugs through the skin.
Among the reasons skin products have not been based on pure phospholipids are that granular and powdered lecithin are not easily applied to the skin, while liquid lecithin, even diluted to 50%, is viscous and not easily spreadable. Because of the unique benefits derived from using pure phospholipid, it would be especially desirable to have a phospholipid composition which is a purified form with the consistency of a cosmetic bar of soap, so that the phospholipid could be applied easily to a user's skin. Further, it would be desirable to have the solid phospholipid bar incorporate dermatological preparations which would be beneficial and advantageous for the treatment of skin ailments and diseases.
In addition, preparations of a solid phospholipid length would be desirable for the oral administration of an almost pure phospholipid nutrient supplement. Meck et al. ("Characterization of the Facilitative Effects of Perinatal Choline Supplementation on Timing and Temporal Memory", Neuroreport (Sep. 8, 1997) 8(13):2831-2835 and (Sep. 29, 1997) 8(14):3045-3059) showed that perinatal choline supplementation has long-term effects on working and reference memory components in rats. Pyapali, G. K. et al., "Prenatal Dietary Choline Supplementation Decreases the Threshold for Induction of Long-Term Potentiation in Young Adult Rats", J. of Neurophysiology (April 1998) 79(4):1790-1796, found that the induction of Long-Term Potentiation was enhanced in adult rats that had received prenatal choline supplementation. Oral lecithin supplements currently are prepared based on either liquid or granular lecithin products. The liquid lecithin products are encapsulated with gelatin and provide an easily consumed product. However, these liquid lecithin products have decreased potency. Formulated liquid lecithin supplements consists most generally of water with a phospholipid content of less than 10%. These lecithin compositions suffer from being microbiologically unstable and require further processing to render them shelf-stable.
Oral supplements based on the higher potency granular lecithin are consumed as powders or granules by mixing with other foods such as ready-to-eat cereals or dissolved in drinks such as fruit juice. These products are difficult to dissolve and generally have an undesirable texture and taste. Formulated dry lecithin supplements for use in milk or juice solids are intended for hydration prior to consumption. These, however, suffer from low potency and high cost.
Thus, it is desirable to have a solid phospholipid composition comprised primarily of phospholipids which: 1) can be used externally to moisturize and protect skin, 2) can be used externally in a mixture with phytochemicals and medicaments for the treatment of skin ailments and, 3) can be formulated into a pill or tablet and taken orally as a nutritional supplement.
Preparations of a solid phospholipid bar also would be desirable for the oral administration of nutraceutical and pharmaceutical drugs. The use of Coenzyme Q10 and lecithin taken orally is given in U.S. Pat. No. 4,684,520 to Bertelli, which describes the combination restoring cerebral function and inhibiting the formation of atherosclerotic lesions. U.S. Pat. No. 4,780,456 to Pistolesi describes a dietetic composition for the treatment of atherosclerotic pathologies which treatment incorporates lecithin and eicosapentaenoic oils. U.S. Pat. No. 5,043,323 to Bombardelli et al. states that the oral consumption of lecithin with plant flavonoids is an effective treatment for inflammation, altered platelet aggregation and other diseases. These referenced compounds may be ingested as capsules, tablets, granules, gels or syrups. However, the beneficial effects of phospholipid are minimal in these products either because the ratio of drugs to phospholipid is too high, or because individual fractions of soy phospholipids are used to produce the compound. Therefore, it is desirable to have a solid composition comprised primarily of phospholipids which, in addition to the uses given above, can be formulated into a pill or tablet that contains drugs and nutritional compositions as additives, which pills and tablets can be taken orally.
Also it would be desirable to have a preparation of solid phospholipid composition in which the dispersibility or release may be controlled through use of modified, high potency lecithin-creating a compound to enhance or delay release of active ingredients.